The deadly new strain of E.coli that has killed 18 people in Europe risks
spreading from person to person in Britain, the Health Protection Agency
warned last night.

As seven cases of the food poisoning bacteria were diagnosed in Britain, the agency said that the mutant strain was so virulent that sufferers risked spreading the infection to friends and relations through close contact.

With more than 30,000 people travelling between Britain and Germany every day, officials fear the outbreak could take hold here.

The agency said anyone who had recently travelled to Germany should be vigilant about their personal hygiene to minimise the risk of passing on the bacteria, which can attack the kidneys with potentially fatal consequences.

The outbreak is on course to be the world’s “biggest ever”, according to one of the country’s leading microbiologists. The agency added that it was shocked by its “unprecedented” scale and severity. More than 1,600 people have been infected worldwide, mainly in northern Germany. Hundreds have been left seriously ill and at least 18 have died.

It emerged last night that the food bug has struck two Americans who had recently travelled to Hamburg. Both are expected to survive but experts warned that the bacteria could be exported to the US.

The World Health Organisation identified the bacterium as a “completely new” mutant strain which was more toxic and infectious than usual varieties. It is resistant to antibiotics and has an eight-day incubation period, which means that the outbreak may not have reached a peak.

It can cause the deadly complication haemolytic-uraemic syndrome (HUS) which affects the blood and kidneys. The Food Standards Agency said that contaminated produce had not entered the British food chain, although several supermarkets confirmed last night that they were still importing produce from Germany.

Experts are still unable to say where the outbreak originated, having ruled out the initial theory that it came from a consignment of Spanish cucumbers. Fears have heightened to such an extent that Russia yesterday banned the import of all raw vegetables from Europe.

The HPA said the seven cases diagnosed in Britain involved people who had recently travelled to Germany. Three are seriously ill with the HUS complication. Dr Bob Adak, an expert in gastrointestinal infections at the agency, said his organisation had interviewed the families of those involved and advised them to take precautions to avoid a secondary spread of the bacteria.

“We’re extremely concerned by it,” he said. “We are on the lookout for secondary infections, because it is quite infectious you don’t need many bacteria on your hand to spread it.

“People have got to be very careful, in the first instance those who are most at risk are other family members. People who have been to Germany and come back should be careful with their hygiene.

“If they experience abdominal cramps or diarrhoea they should seek medical advice. This illness can develop and spread very quickly. If you have young children in the house you want to protect them.”

E.coli is usually contracted by eating contaminated food, but it can spread from person to person if the strain is infectious enough. People must be particularly careful to wash their hands thoroughly after using the lavatory.

Hilde Kruse, a food safety expert at the WHO, said the strain had characteristics which made it “more

virulent and toxin-producing”. Preliminary genetic sequencing suggests that the strain is a new, mutant form of two different E.coli bacteria, according to the WHO. “This is a unique strain that has never been isolated from patients before,” Miss Kruse added.

Unlike previous outbreaks, this strain of E.coli mainly attacks women rather than children or elderly people. More than three quarters of those suffering from serious kidney problems are adult women. Dr Adak added: “The most simple explanation is that because women tend to eat more salad than men and children their risk becomes higher.”

Dr Alexander Mellmann, the scientist who mapped the DNA of the bacteria at the University of Munster in Germany, told The Daily Telegraph that the bacteria had evolved to become more toxic and better at “sticking” to human cells, increasing the chance of infection.

Scientists believe the strain originated in animals such as cattle before spreading to vegetables. The HPA is advising people travelling to Germany to wash salads and to avoid eating raw tomatoes, cucumbers and leafy salads.

Tesco yesterday said it has “small quantities” of cauliflower, cabbage and sweetcorn from Germany in its stores, adding that its suppliers observe the “strictest hygiene standards”. Lidl said it stocks cauliflower from Germany.

The seven people infected in the UK include four German nationals and three British people who recently visited Germany. Three of them are seriously ill with HUS. The other four have suffered from bloody diarrhoea.

Germany has reported 470 cases of HUS and 1,064 cases of bloody diarrhoea. Austria, Denmark, Germany, the Netherlands, Norway, Spain, Sweden and Switzerland have also reported cases, almost all in people who have just returned from Germany.

The Food Standards Agency in Britain has issued general advice on the need to wash fruit and vegetables. Peeling or cooking fruit and vegetables is also known to help remove germs.